The 13-part series, starring Colin Morgan as Merlin, with Bradley James as King Arthur, Angel Coulby as Gwen, Katie McGrath as Morgana, Richard Wilson as Gaius, and John Hurt as the voice of the Great Dragon, starts on BBC One on Saturday 6th October at 7.45pm. Returning as the Knights of the Round Table are Tom Hopper (Sir Percival), Rupert Young (Sir Leon), Eoin Macken (Sir Gwaine), and Adetomiwa Edun (Sir Elyan), as pictured below.

When a stranger gives Arthur the power to summon the dead, the king finds himself torn between head and heart.

Unable to resist temptation, he seizes the chance to speak to the person he misses most – his father, Uther Pendragon. But the spirit world is a dark and dangerous place, for little does Arthur realise that his decision comes at a terrible price. Against all odds, Merlin must put right Arthur's mistake before Camelot - and everything they have built - is destroyed forever.

Episode 3 is currently scheduled for 7.45pm on Saturday 20th October. Episode 2 has now been confirmed for 8.25pm on Saturday 13th October, having been moved from the 7.45pm slot that was provisionally announced by the BBC.